College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400716, China.
Citrus Research Institute, Chinese Academy of Agricultural Sciences, Chongqing 400712, China.
Molecules. 2019 May 6;24(9):1755. doi: 10.3390/molecules24091755.
To investigate the effect of post-harvest light irradiation on the accumulation of flavonoids and limonoids, harvested Newhall navel oranges were continuously exposed to light-emitting diode (LED) and ultraviolet (UV) light irradiation for 6 days, and the composition and content of flavonoids and limonoids in the segments were determined using UPLC-qTOF-MS at 0, 6, and 15 days after harvest. In total, six polymethoxylated flavonoids (PMFs), five flavone-/-glycosides, seven flavanone--glycosides, and three limonoids were identified in the segments. The accumulation of these components was altered by light irradiation. Red and blue light resulted in higher levels of PMFs during exposure periods. The accumulation of PMFs was also significantly induced after white light, UVB and UVC irradiation were removed. Red and UVC irradiation induced the accumulation of flavone and flavanone glycosides throughout the entire experimental period. Single light induced limonoid accumulation during exposure periods, but limonoid levels decreased significantly when irradiation was removed. Principal component analysis showed a clear correlation between PMFs and white light, between flavonoid glycosides and red light and UVC, and between limonoids and UVC. These results suggest that the accumulation of flavonoids and limonoids in citrus is regulated by light irradiation. White light, red light and UVC irradiation might be a good potential method for improving the nutrition and flavor quality of post-harvest citrus.
为了研究采后光照对类黄酮和柠檬苦素积累的影响，将收获的新奇士脐橙连续暴露于发光二极管（LED）和紫外线（UV）光下 6 天，并在收获后 0、6 和 15 天使用 UPLC-qTOF-MS 测定各部位类黄酮和柠檬苦素的组成和含量。共鉴定出 6 种多甲氧基黄酮（PMFs）、5 种黄酮苷、7 种黄烷酮糖苷和 3 种柠檬苦素。光照处理改变了这些成分的积累。红蓝光照射期 PMFs 水平较高。在去除白光、UVB 和 UVC 照射后，PMFs 的积累也显著增加。红蓝光和 UVC 辐射诱导整个实验期间黄酮和黄烷酮糖苷的积累。单一光照在照射期诱导柠檬苦素的积累，但当光照去除时，柠檬苦素水平显著下降。主成分分析表明，PMFs 与白光、类黄酮糖苷与红光和 UVC 之间以及柠檬苦素与 UVC 之间存在明显的相关性。这些结果表明，柑橘类水果中类黄酮和柠檬苦素的积累受光照调控。白光、红光和 UVC 辐射可能是提高采后柑橘营养和风味品质的一种潜在方法。
